[DTrace-devel] [PATCH 05/13] Handle steps==0 error for llquantize

[eugene.loh at oracle.com]

From: Eugene Loh <eugene.loh at oracle.com>

We can get divide-by-zero failures if we do not explicitly check.

Signed-off-by: Eugene Loh <eugene.loh at oracle.com>
---
 libdtrace/dt_cg.c                             |  2 +-
 .../aggs/err.D_LLQUANT_STEPVAL.llqstepszero.d | 20 +++++++++++++++++++
 2 files changed, 21 insertions(+), 1 deletion(-)
 create mode 100644 test/unittest/aggs/err.D_LLQUANT_STEPVAL.llqstepszero.d

diff --git a/libdtrace/dt_cg.c b/libdtrace/dt_cg.c
index 29426d23..673b9794 100644
--- a/libdtrace/dt_cg.c
+++ b/libdtrace/dt_cg.c
@@ -3216,7 +3216,7 @@ dt_cg_agg_llquantize(dt_pcb_t *pcb, dt_ident_t *aid, dt_node_t *dnp,
 			"must be an unsigned 16-bit quantity\n");
 
 	if (steps < factor) {
-		if (factor % steps != 0)
+		if (steps == 0 || factor % steps != 0)
 			dnerror(arg1, D_LLQUANT_STEPVAL, "llquantize() "
 				"argument #4 (steps) must evenly divide "
 				"argument #1 (factor) when steps<factor\n");
diff --git a/test/unittest/aggs/err.D_LLQUANT_STEPVAL.llqstepszero.d b/test/unittest/aggs/err.D_LLQUANT_STEPVAL.llqstepszero.d
new file mode 100644
index 00000000..f2b0f442
--- /dev/null
+++ b/test/unittest/aggs/err.D_LLQUANT_STEPVAL.llqstepszero.d
@@ -0,0 +1,20 @@
+/*
+ * Oracle Linux DTrace.
+ * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * Licensed under the Universal Permissive License v 1.0 as shown at
+ * http://oss.oracle.com/licenses/upl.
+ */
+
+/*
+ * ASSERTION:
+ *  llquantize() steps must be nonzero.
+ *
+ * SECTION: Aggregations/Aggregations
+ *
+ */
+
+
+BEGIN
+{
+	@ = llquantize(timestamp, 10, 0, 6, 0);
+}
-- 
2.18.4